Division of Epidemiology, School of Public Health, University of California, Berkeley, CA, USA.
Center for Communicable Disease Dynamics, Harvard TH Chan School of Public Health, Boston, MA, USA.
Lancet Infect Dis. 2019 Jun;19(6):e213-e220. doi: 10.1016/S1473-3099(18)30660-1. Epub 2019 Jan 29.
Serotype replacement in invasive pneumococcal disease threatens to undermine the most costly vaccination programme currently undertaken. However, the effects of replacement on public health have varied geographically. Striking differences have emerged between the UK and USA, countries that otherwise often resemble each other epidemiologically. Similar to other European settings, the UK has had rising non-vaccine serotype invasive pneumococcal disease, most notably in older adults, since introducing a 13-valent pneumococcal conjugate vaccine to the paediatric immunisation schedule. Such impacts of serotype replacement have not been reported in the USA, where incidence of non-vaccine serotype invasive pneumococcal disease in young children and older people has been stable since the introduction of the same vaccine. Here, we explore factors that have been suggested to account for these differences, including surveillance practices, transmission dynamics, population risk factors, and pathogen evolution. We contend that none of these factors individually appears sufficient to account for the observed differences. Assessing the existing evidence, we define priorities for research and data collection to discern causes and inform future pneumococcal vaccine policy.
血清型替换在侵袭性肺炎球菌病中构成威胁，可能破坏目前正在开展的最昂贵的疫苗接种计划。然而，替换对公共卫生的影响在地域上存在差异。在英国和美国这两个在流行病学上通常相似的国家之间，出现了显著的差异。与其他欧洲国家类似，自将 13 价肺炎球菌结合疫苗纳入儿童免疫接种计划以来，英国侵袭性非疫苗血清型肺炎球菌病的发病率一直在上升，尤其是在老年人中。在美国，自引入相同疫苗以来，儿童和老年人中侵袭性非疫苗血清型肺炎球菌病的发病率一直保持稳定，尚未报告出现血清型替换的这种影响。在这里，我们探讨了一些被认为可以解释这些差异的因素，包括监测实践、传播动态、人群风险因素和病原体进化。我们认为，这些因素单独来看，都不足以解释观察到的差异。在评估现有证据的基础上，我们确定了研究和数据收集的优先事项，以查明原因并为未来的肺炎球菌疫苗政策提供信息。
